Printed circuit board and preparation method thereof

Abstract

The invention discloses a printed circuit board and a preparation method thereof, and the method comprises the steps: obtaining a first plate and a second plate, and the first plate comprises a temporary substrate and a target conductive circuit disposed at one side of the temporary substrate in an attached manner; the second plate comprises a dielectric layer and a conductive layer; placing the target conductive circuit of the first plate on the dielectric layer of the second plate, and performing lamination processing to enable the side surface of the target conductive circuit to be embedded into the dielectric layer to obtain a laminated plate; and removing the temporary substrate, and taking the target conductive circuit as an outer circuit to obtain the printed circuit board. Through the mode, the impedance control difficulty of the outer layer circuit of the printed circuit board can be reduced, the impedance control precision of the outer layer circuit of the printed circuit board can be improved, and the printed circuit board can conveniently meet the requirements of high-frequency and high-speed products.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of printed circuit boards, and particularly relates to a printed circuit board and a preparation method thereof. BACKGROUND

[0002] PCB (Printed Circuit Board), also known as printed wiring board, is an important electronic component, is a support body of electronic components, and is a carrier of electrical interconnection of electronic components.

[0003] In the manufacturing process of the printed circuit board, the impedance control of the outermost layer of high-speed wiring has always been a difficulty in processing, especially affected by the plating copper thickness, the accurate control of the line width and the line spacing of the surface layer of high-speed wiring becomes extremely difficult.

[0004] The reason is that the unevenness of the plating copper thickness will cause the actual width and spacing of the wiring to deviate from the design value, and the high-speed signal has extremely high requirements for impedance matching, so even a slight change in the line width and the line spacing will cause significant fluctuations in the impedance. SUMMARY

[0005] The application provides a printed circuit board and a preparation method thereof, to solve the problem that the impedance of the outer layer of the printed circuit board is difficult to control.

[0006] To solve the above technical problems, the application provides a preparation method of a printed circuit board, comprising: obtaining a first board piece and a second board piece, the first board piece comprising a temporary substrate and a target conductive circuit attached to one side of the temporary substrate; the second board piece comprising a dielectric layer and a conductive layer; placing the target conductive circuit of the first board piece on the dielectric layer of the second board piece and performing a pressing process, so that the side surface of the target conductive circuit is embedded in the dielectric layer, to obtain a pressed board piece; removing the temporary substrate to take the target conductive circuit as an outer layer circuit, to obtain a printed circuit board.

[0007] Among them, obtaining the first board piece comprises: obtaining a target conductive layer, attaching a temporary substrate to one side of the target conductive layer; attaching a first protective layer to the other side of the target conductive layer, and sequentially preparing the target conductive layer into a target conductive circuit by an exposure, development and etching method, removing the first protective layer, to obtain the first board piece.

[0008] Among them, the temporary substrate comprises a tin layer, and the temporary substrate is attached to one side of the target conductive layer, comprising: tin plating is performed on one side of the target conductive layer until the tin layer covers one side of the target conductive layer, to form the temporary substrate.

[0009] The method comprises the following steps: removing the temporary substrate to take the target conductive circuit as an outer circuit to obtain a printed circuit board, comprising: removing the temporary substrate and adhering a second protective layer on the side of the target conductive circuit away from the laminated board; electroplating the laminated board to form an electroplated layer on the outer layer of the laminated board; etching the electroplated layer to remove the electroplated layer on the side of the second protective layer away from the target conductive circuit; removing the second protective layer to expose the target conductive circuit to form the outer circuit to obtain the printed circuit board.

[0010] The method comprises the following steps: removing the temporary substrate to take the target conductive circuit as an outer circuit to obtain a printed circuit board, comprising: removing the temporary substrate and adhering a second protective layer on the side of the target conductive circuit away from the laminated board; electroplating the laminated board to form an electroplated layer on the outer layer of the laminated board; etching the electroplated layer to remove the electroplated layer on the side of the second protective layer away from the target conductive circuit; removing the second protective layer to expose the target conductive circuit to form the outer circuit to obtain the printed circuit board.

[0011] The method comprises the following steps: removing the temporary substrate to take the target conductive circuit as an outer circuit to obtain a printed circuit board, comprising: removing the temporary substrate and adhering a second protective layer on the side of the target conductive circuit away from the laminated board; electroplating the laminated board to form an electroplated layer on the outer layer of the laminated board; etching the electroplated layer to remove the electroplated layer on the side of the second protective layer away from the target conductive circuit; removing the second protective layer to expose the target conductive circuit to form the outer circuit to obtain the printed circuit board.

[0012] The method comprises the following steps: removing the temporary substrate to take the target conductive circuit as an outer circuit to obtain a printed circuit board, comprising: removing the temporary substrate and adhering a second protective layer on the side of the target conductive circuit away from the laminated board; electroplating the laminated board to form an electroplated layer on the outer layer of the laminated board; etching the electroplated layer to remove the electroplated layer on the side of the second protective layer away from the target conductive circuit; removing the second protective layer to expose the target conductive circuit to form the outer circuit to obtain the printed circuit board.

[0013] The method comprises the following steps: removing the temporary substrate to take the target conductive circuit as an outer circuit to obtain a printed circuit board, comprising: removing the temporary substrate and adhering a second protective layer on the side of the target conductive circuit away from the laminated board; electroplating the laminated board to form an electroplated layer on the outer layer of the laminated board; etching the electroplated layer to remove the electroplated layer on the side of the second protective layer away from the target conductive circuit; removing the second protective layer to expose the target conductive circuit to form the outer circuit to obtain the printed circuit board.

[0014] The method comprises the following steps: removing the temporary substrate to take the target conductive circuit as an outer circuit to obtain a printed circuit board, comprising: removing the temporary substrate and adhering a second protective layer on the side of the target conductive circuit away from the laminated board; electroplating the laminated board to form an electroplated layer on the outer layer of the laminated board; etching the electroplated layer to remove the electroplated layer on the side of the second protective layer away from the target conductive circuit; removing the second protective layer to expose the target conductive circuit to form the outer circuit to obtain the printed circuit board.

[0015] The method comprises the following steps: removing the temporary substrate to take the target conductive circuit as an outer circuit to obtain a printed circuit board, comprising: removing the temporary substrate and adhering a second protective layer on the side of the target conductive circuit away from the laminated board; electroplating the laminated board to form an electroplated layer on the outer layer of the laminated board; etching the electroplated layer to remove the electroplated layer on the side of the second protective layer away from the target conductive circuit; removing the second protective layer to expose the target conductive circuit to form the outer circuit to obtain the printed circuit board.

[0016] To solve the above technical problems, the preparation method of the printed circuit board provided by the present application obtains a first plate and a second plate, the first plate comprises a temporary substrate and a target conductive circuit arranged on one side of the temporary substrate; the second plate comprises a dielectric layer and a conductive layer; the target conductive circuit of the first plate is placed on the dielectric layer of the second plate, and a pressing process is performed to embed the side surface of the target conductive circuit into the dielectric layer, thereby obtaining a pressed plate; the temporary substrate is removed to take the target conductive circuit as an outer layer circuit, thereby obtaining a printed circuit board. Thus, the target conductive circuit is prepared in advance on the temporary substrate, which can be prepared independently, facilitating the adjustment of thickness and spacing, and can facilitate the direct preparation of the target conductive circuit in a subtractive manner, thereby improving the consistency of the thickness and the accuracy of the spacing of the target conductive circuit by using the whole plate structure before subtracting, so as to reduce the difficulty of impedance control of the outer layer circuit of the printed circuit board and improve the accuracy of the impedance control of the outer layer circuit of the printed circuit board, thereby facilitating the realization of the demand of high-frequency and high-speed products of the printed circuit board. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a flowchart of an embodiment of the preparation method of the printed circuit board provided by the present application;

[0018] Figure 2 is a flowchart of another embodiment of the preparation method of the printed circuit board provided by the present application;

[0019] Figure 3 is Figure 2 is a structure diagram of the upper half of the preparation method in the embodiment;

[0020] Figure 4 is Figure 2 is a structure diagram of the lower half of the preparation method in the embodiment;

[0021] Figure 5 is a structure diagram of an embodiment of the printed circuit board provided by the present application. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0023] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications will also change accordingly.

[0024] In addition, if the embodiments of the present application involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of a person skilled in the art, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the protection scope required by the present application.

[0025] Please refer to Figure 1 , Figure 1 is a flowchart of an embodiment of the method for manufacturing a printed circuit board provided by the present application.

[0026] Step S11: Obtain a first plate and a second plate. The first plate includes a temporary substrate and a target conductive circuit attached to one side of the temporary substrate. The second plate includes a dielectric layer and a conductive layer.

[0027] The temporary substrate is a rigid and subsequently removable substrate, including but not limited to a metal substrate, a glass substrate, a plastic substrate, a ceramic substrate, etc. of different materials from the target conductive circuit, without limitation. The temporary substrate is used as a support substrate for the target conductive circuit in this step to ensure that the target conductive circuit does not deform during the manufacturing process.

[0028] The target conductive circuit is an outer layer circuit of the subsequent printed circuit board. By preparing the target conductive circuit on the temporary substrate in advance, the thickness and spacing of the target conductive circuit are fixed, the stability of the target conductive circuit is improved, and the difficulty of impedance control of the target conductive circuit is reduced.

[0029] In a specific application scenario, the target conductive layer on one side of the temporary substrate can be prepared into a target conductive circuit by etching or local depth control, thereby facilitating the consistency of the thickness and the accuracy of the spacing of the target conductive circuit. In a specific application scenario, the thickness and spacing of the target conductive circuit can be adjusted after the target conductive circuit is prepared, so as to meet the requirements. When the target conductive circuit is arranged on one side of the temporary substrate, the thickness and spacing of the target conductive circuit can be controlled in various ways, thereby facilitating the stability of the target conductive circuit, and thereby reducing the difficulty of impedance control of the target conductive circuit.

[0030] The second plate member includes a dielectric layer and a conductive layer. The dielectric layer can include, but is not limited to, one or more of prepreg, epoxy resin, polyester resin (PET), polyimide, polyimide, polycarbonate (PC), bismaleimide triazine (BT), Ajinomoto build film (ABF), FR4 resin, ceramic-based insulating materials, etc. The conductive layer can include, but is not limited to, a copper layer, an aluminum layer, a silver layer, an alloy layer, etc.

[0031] Step S12: Place the target conductive circuit of the first plate member on the dielectric layer of the second plate member and perform a pressing process to embed the side surface of the target conductive circuit into the dielectric layer to obtain a pressed plate member.

[0032] In a specific application scenario, the second plate member can include a dielectric layer and a conductive layer, and the dielectric layer and the conductive layer can be stacked, specifically, they can be attached or not attached. The target conductive circuit of the first plate member is placed on the dielectric layer of the second plate member, and a pressing process is performed to obtain a pressed plate member in which the first plate member, the dielectric layer, and the conductive layer are stacked in sequence. Since there is a spacing gap between the target conductive circuits, the side surface of the target conductive circuit will be embedded in the dielectric layer. After pressing, the target conductive circuit embedded in the dielectric layer will be fixed, and the structural stability and reliability will be improved. The pressed plate member can be further pressed with other plate members to meet the layer number requirement of the printed circuit board.

[0033] In a specific application scenario, the second plate member can include a plurality of dielectric layers and a plurality of conductive layers arranged alternately. The target conductive circuit of the first plate member is placed on the dielectric layer of the outer layer of the second plate member, and a pressing process is performed to obtain a pressed plate member. Since the second plate member can include multiple layers, when the first plate member is pressed with the second plate member, the layer number requirement of the printed circuit board can be met. Since there is a spacing gap between the target conductive circuits, the side surface of the target conductive circuit will be embedded in the dielectric layer. After pressing, the target conductive circuit embedded in the dielectric layer will be fixed, and the structural stability and reliability will be improved.

[0034] The number of layers of the second plate member is set based on actual requirements, which is not limited here.

[0035] During the pressing process, the temporary substrate can also serve as a pressing plate to receive the force of the pressing machine and press the target conductive circuit into the dielectric layer for fixation.

[0036] Step S13: Remove the temporary substrate to obtain the printed circuit board with the target conductive circuit as the outer layer circuit.

[0037] After the target conductive circuit is embedded in the dielectric layer, the temporary substrate is removed to expose the target conductive circuit as the outer layer circuit. At this time, the outer layer circuit has high thickness consistency and good spacing accuracy.

[0038] In a specific application scenario, if the pressed plate member meets the number of layers requirement of the printed circuit board at this time, the printed circuit board can be obtained. In a specific application scenario, if the pressed plate member does not meet the number of layers requirement of the printed circuit board at this time, multiple layers of plates can be pressed on the side of the pressed plate member away from the target conductive circuit to obtain the printed circuit board. The specific application scenario is not limited here.

[0039] Through the above steps, the preparation method of the printed circuit board of the embodiment obtains the first plate member and the second plate member, the first plate member includes the temporary substrate and the target conductive circuit attached to one side of the temporary substrate; the second plate member includes the dielectric layer and the conductive layer; the target conductive circuit of the first plate member is placed on the dielectric layer of the second plate member and subjected to pressing treatment to embed the side surface of the target conductive circuit into the dielectric layer to obtain a pressed plate member; the temporary substrate is removed to obtain the printed circuit board with the target conductive circuit as the outer layer circuit. Thus, the target conductive circuit is prepared on the temporary substrate in advance, which can be prepared independently from the target conductive circuit, facilitating thickness and spacing adjustment, and can be directly prepared by subtractive method, which can improve the thickness consistency and spacing accuracy of the target conductive circuit using the whole plate structure before subtractive, thereby reducing the impedance control difficulty of the outer layer circuit of the printed circuit board and improving the impedance control accuracy of the outer layer circuit of the printed circuit board, facilitating the realization of high-frequency high-speed products of the printed circuit board.

[0040] Please refer to Figures 2-4 , Figure 2 is the flowchart of another embodiment of the preparation method of the printed circuit board provided by the present application. Figure 3 is Figure 2 the upper half flowchart of the preparation method in the embodiment. Figure 4 is Figure 2 the lower half flowchart of the preparation method in the embodiment.

[0041] Step S21: Obtain the target conductive layer, and adhere a temporary substrate to one side of the target conductive layer.

[0042] The target conductive layer is an integral conductive layer, and the temporary substrate is adhered to one side of the target conductive layer. The target conductive layer can be a single copper foil layer or other conductive metal layer.

[0043] In a specific application scenario, the temporary substrate can be a tin layer, and then tinning can be performed on one side of the target conductive layer until the tin layer covers one side of the target conductive layer to form the temporary substrate. In other application scenarios, the temporary substrate can also be other rigid removable materials, which are not limited here.

[0044] Step S22: Adhere a first protective layer to the other side of the target conductive layer, and then prepare the target conductive layer into a target conductive circuit by means of exposure, development and etching, remove the first protective layer, and obtain a first plate.

[0045] The first protective layer can be a dry film or other photosensitive layer, and the step of setting the first protective layer can be exchanged with the step of adhering the temporary substrate in step S21, which is set based on actual conditions.

[0046] Specifically, positioning holes can be set on the target conductive layer before setting the first protective layer to improve the accuracy of subsequent exposure and development. The positioning holes can be set at the four corner positions of the target conductive layer to achieve positioning function and prevent affecting the preparation of the target conductive circuit.

[0047] After the first protective layer is set, the target conductive layer is prepared into a target conductive circuit by means of exposure, development and etching. Before exposure, the required line width and distance can be calculated according to the impedance requirement for corresponding exposure.

[0048] The first protective layer is removed to obtain a first plate. The above subtractive method for preparing the target conductive circuit can improve the thickness consistency of the target conductive circuit by using the thickness consistency of the target conductive layer, and can improve the spacing accuracy of the target conductive circuit by determining the circuit shape through exposure and development.

[0049] Please refer to Fig. 3a in the specification Figure 3 The first plate 30 includes the adhered temporary substrate 31 and the target conductive circuit 32. The thickness consistency and spacing accuracy of the target conductive circuit 32 are improved.

[0050] Step S23: Place the target conductive circuit of the first plate on the dielectric layer of the second plate, and perform a pressing process to embed the side surface of the target conductive circuit into the dielectric layer to obtain a pressed plate.

[0051] This embodiment uses a second board comprising a single dielectric layer and a single conductive layer as an example for illustration. Please refer to further reading. Figure 3 In step 3b, based on step 3a, the target conductive line 32 of the first plate 30 is placed on the dielectric layer 33 of the second plate 35 and then pressed together so that the side of the target conductive line 32 is embedded in the dielectric layer 33, resulting in a pressed plate 36.

[0052] Because there are gaps between the target conductive lines 32, a dielectric layer 33 is embedded in the side of the target conductive lines 32. After pressing, the target conductive lines 32 with the embedded dielectric layer 33 are fixed in place, and their structural stability and reliability are improved.

[0053] This step first involves pressing the target conductive line 32 to the single-layer second plate 35, thereby pre-curing and shaping the dielectric layer 33 corresponding to the target conductive line 32. This ensures that its thickness will not change during subsequent pressing, thus completely fixing the impedance of the target conductive line 32 and achieving impedance control. The dielectric layer 33 is a one-time curing material and will not deform even if it is subsequently hot-pressed.

[0054] Step S24: Remove the temporary substrate and attach a second protective layer to the side of the target conductive line away from the laminate.

[0055] The second protective layer includes, but is not limited to, tin layers, dry films, resist layers, and metal layers of non-conductive circuit materials, etc., and is used to protect the target conductive lines during subsequent etching processes to stabilize the structural stability and impedance of the target conductive lines.

[0056] Please refer to further information. Figure 3 In step 3c, based on step 3b, a tin layer 37 is used as a second protective layer 38. Specifically, the temporary substrate 31 is first removed to expose the target conductive line 32, and tin is plated on the side of the target conductive line 32 away from the laminating plate 36 until the tin layer 37 covers the side of the target conductive line 32 away from the laminating plate 36, thus obtaining the second protective layer 38. The target conductive line 32 is protected by the second protective layer 38 to stabilize the structural stability and impedance of the target conductive line 32.

[0057] When tinning the target conductive line 32, a protective layer can be applied to the conductive layer 34 to prevent it from being tinned as well. After tinning is complete, the protective layer on the conductive layer 34 is removed.

[0058] The method for removing the temporary substrate 31 is selected based on its material. For example, alkaline solution etching, thermal bonding, or mechanical separation can be selected, and no limitation is made here.

[0059] Step S25: re-pressing the at least one pressed board away from the side of the target conductive circuit of the multi-layer board to obtain an overall board meeting the requirement of the number of layers of the printed circuit board.

[0060] Since the second board is taken as a single-layer board in the embodiment, the number of layers of the overall board before the step may not meet the requirement, and the step is taken to re-press to meet the requirement of the number of layers.

[0061] Please further refer to Figure 3 3d in FIG. 3, 3d is based on 3c, and the at least one pressed board 36 is re-pressed away from the side of the target conductive circuit 32 of the multi-layer board 40 to obtain an overall board 41 meeting the requirement of the number of layers of the printed circuit board. Before pressing, the pattern circuit of the conductive layer 34 can be prepared, and then the pressing is performed.

[0062] In a specific application scenario, if the impedance control needs to be implemented on only one side of the outer circuit of the printed circuit board, one pressed board 36 is pressed with one side of the multi-layer board in the step; if the impedance control needs to be implemented on the outer circuits of the opposite sides of the printed circuit board, two pressed boards 36 are pressed with the opposite sides of the multi-layer board 40, respectively, and the embodiment is taken as an example for description of one side.

[0063] In the pressing of the step, since the pressed board 36 has been pre-pressed and solidified, the thickness of the dielectric layer 33 corresponding to the target conductive circuit 32 is unchanged in the pressing to ensure that the impedance of the target conductive circuit 32 is unchanged.

[0064] Step S26: preparing at least one via hole on the overall board; and electroplating the overall board to metalize the via hole and form an electroplated layer on the opposite sides of the overall board.

[0065] Please further refer to Figure 3 3e in FIG. 3, 3e is based on 3d, at least one via hole 42 is prepared on the overall board 41, and the overall board 41 is electroplated to metalize the via hole 42 and form an electroplated layer 43 on the opposite sides of the overall board 41.

[0066] The number of the via hole 42 is set based on the requirement of the printed circuit board, and is not limited herein.

[0067] In a specific application scenario, if the back drilling is required for the via hole 42, at least part of the metalized via hole 42 is back drilled, and the resin is plugged into each via hole. If the back drilling is not required, the back drilling related steps are ignored.

[0068] Please further refer to Figure 33f, 3f is based on 3e, back drilling processing is performed on the at least partially metallized through hole 42, and resin plug holes are respectively formed in each through hole 42 to meet the interlayer interconnection requirement of the through hole 42.

[0069] Step S27: Etching processing is performed on the electroplated layer, and the electroplated layer on the side of the second protective layer away from the target conductive circuit is removed.

[0070] Please further refer to Figure 4 4a, 4a is based on 3f, etching processing is performed on the electroplated layer 43, and the electroplated layer 43 on the side of the second protective layer 38 away from the target conductive circuit 32 is removed. Specifically, etching processing is performed on the electroplated layer 43 to form a surface pad 45 or other non-conductive circuit electrical structure, and the electroplated layer 43 on the side of the second protective layer 38 away from the target conductive circuit is etched and removed; wherein the surface pad 45 is arranged at intervals with the target conductive circuit 32.

[0071] Step S28: The second protective layer is removed to expose the target conductive circuit, forming an outer layer circuit to obtain a printed circuit board.

[0072] Please further refer to Figure 4 4b, 4b is based on 4a, tin removal processing is performed on the second protective layer 38 to remove the target conductive circuit 32 exposed by the second protective layer 38 to form an outer layer circuit of the printed circuit board.

[0073] The tin removal processing can be nitric acid etching, fluoroboric acid etching, etc., which is not limited here.

[0074] Finally, the opposite sides of the printed circuit board are subjected to solder mask processing for surface circuit protection.

[0075] Through the above steps, the preparation method of the printed circuit board of the present embodiment can independently prepare the target conductive circuit by preparing the target conductive circuit on the temporary substrate in advance, facilitate the adjustment of the thickness and the spacing, and can directly prepare the target conductive circuit by using the exposure development etching method, can improve the consistency of the thickness and the accuracy of the spacing of the target conductive circuit by using the whole plate structure of the target conductive layer before etching, thereby reducing the difficulty of impedance control of the outer layer circuit of the printed circuit board, and after the target conductive circuit is prepared, the single-layer second plate is pressed first to fix the thickness of the dielectric layer corresponding to the target conductive circuit, and then the position of the target conductive circuit is fixed, that is, the impedance of the target conductive circuit is fixed, reducing the change of the target conductive circuit in the subsequent preparation process, reducing the difficulty of impedance control of the outer layer circuit, improving the impedance control accuracy of the outer layer circuit of the printed circuit board, and facilitating the printed circuit board to meet the demand of high-frequency high-speed products.

[0076] Please refer to Figure 5 ,Figure 5 is a structural schematic diagram of an embodiment of the printed circuit board provided by the present application.

[0077] The side surface of the outer layer circuit 51 of at least one side of the printed circuit board 50 is embedded in the corresponding dielectric layer 52, and in this embodiment, one side is taken as an example for illustration. In other embodiments, the side surface of the outer layer circuit 51 of the opposite two sides of the printed circuit board 50 is embedded in the corresponding dielectric layer 52. In this embodiment, the printed circuit board 50 is prepared by the preparation method of any one of the printed circuit boards described above.

[0078] Through the above structure, the thickness consistency and the spacing precision of the outer layer circuit of the printed circuit board of this embodiment are high, thereby realizing high impedance control precision.

[0079] In some embodiments, at least one via hole 53 is arranged on the printed circuit board 50, and the number of connection layers of the via hole 53 is set based on actual requirements, which is not limited herein.

[0080] In some embodiments, the opposite two sides of the printed circuit board 50 are further provided with a solder mask layer 54 to protect the outer layer circuit 51.

[0081] The above description is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent flow transformation obtained by using the content of the specification and drawings, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. A method for manufacturing a printed circuit board, characterized in that, The method for manufacturing the printed circuit board includes: A first board and a second board are obtained. The first board includes a temporary substrate and a target conductive line attached to one side of the temporary substrate. The second board includes a dielectric layer and a conductive layer. The target conductive line of the first board is placed on the dielectric layer of the second board and then laminated to embed the side of the target conductive line into the dielectric layer, thus obtaining a laminated board. The temporary substrate is removed to make the target conductive lines the outer layer, resulting in a printed circuit board.

2. The method for preparing a printed circuit board according to claim 1, characterized in that, The acquisition of the first board includes: The target conductive layer is obtained, and the temporary substrate is attached to one side of the target conductive layer. A first protective layer is attached to the other side of the target conductive layer. The target conductive layer is then fabricated into the target conductive circuit by exposure, development and etching. The first protective layer is then removed to obtain the first board.

3. The method for preparing a printed circuit board according to claim 2, characterized in that, The temporary substrate includes a tin layer, and the temporary substrate is attached to one side of the target conductive layer, comprising: Tin plating is performed on one side of the target conductive layer until the tin layer covers one side of the target conductive layer, forming the temporary substrate.

4. The method for manufacturing a printed circuit board according to any one of claims 1-3, characterized in that, The step of removing the temporary substrate to obtain a printed circuit board by using the target conductive lines as outer layers includes: Remove the temporary substrate and attach a second protective layer to the side of the target conductive line away from the laminated plate. The pressed plate is electroplated, and an electroplated layer is formed on the outer layer of the pressed plate. The electroplated layer is etched to remove the electroplated layer on the side of the second protective layer away from the target conductive line; The second protective layer is removed to expose the target conductive lines, forming the outer layer lines to obtain a printed circuit board.

5. The method for preparing a printed circuit board according to claim 4, characterized in that, The step of electroplating the pressed plate and forming an electroplated layer on the outer layer of the pressed plate includes: At least one of the pressed board components is pressed again with a multilayer board on the side away from the target conductive line to obtain an integral board component that meets the printed circuit board layer requirement. At least one through hole is formed on the integral plate; The integral plate is electroplated to metallize the through holes and to form electroplated layers on opposite sides of the integral plate.

6. The method for manufacturing a printed circuit board according to claim 5, characterized in that, The process of electroplating the integral plate to metallize the through holes and forming electroplated layers on opposite sides of the integral plate includes: The partially metallized through holes are back-drilled, and each of the through holes is then plugged with resin.

7. The method for preparing a printed circuit board according to claim 4, characterized in that, The provision of a second protective layer on the side of the target conductive line away from the pressed plate includes: Tin plating is performed on the side of the target conductive line away from the lamination plate until the tin layer covers the side of the target conductive line away from the lamination plate to obtain the second protective layer; The removal of the second protective layer includes: The second protective layer is detinned to remove it.

8. The method for preparing a printed circuit board according to claim 4, characterized in that, The etching process of the electroplated layer, and the removal of the electroplated layer on the side of the second protective layer away from the target conductive line, includes: The electroplated layer is etched to form surface pads, and the electroplated layer on the side of the second protective layer away from the target conductive line is etched away; wherein the surface pads are spaced apart from the target conductive line.

9. The method for manufacturing a printed circuit board according to claim 1, characterized in that, The step of removing the temporary substrate to use the target conductive lines as outer layer circuitry to obtain a printed circuit board further includes: Solder resist is applied to the opposite sides of the printed circuit board to protect the surface circuitry.

10. A printed circuit board, characterized in that, The printed circuit board is prepared by the method of preparing a printed circuit board according to any one of claims 1-9, wherein a corresponding dielectric layer is embedded in the side of the outer layer circuit of at least one side of the printed circuit board.

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